A meta-analysis of randomized controlled trials of intracoronary gamma- and beta-radiation therapy for in-stent restenosis

We assessed the effectiveness of intracoronary brachytherapy and compared treatment effects for the two radiation sources as well as the performance of the procedure in saphenous vein grafts (SVG) and native coronary arteries. Five randomized controlled trials comparing intracoronary brachytherapy with placebo involving a total of 1310 patients were reviewed for a meta-analysis. Risk differences (RD) for major adverse cardiac events (MACE), target vessel revascularization, target lesion revascularization, and angiographic binary restenosis at 6-12 months were computed, and a meta-regression analysis of MACE was performed. For MACE, the RD was 0.19 (95% confidence interval [CI], 0.09%-0.29%; P value, 0.00); there was significant between-study variance of 0.2395. In univariate meta-regression analyses, diabetes was a significant factor for the between-study variance (P value, 0.000). In multivariate meta-regression analyses adjusted for diabetes and lesion length, neither gamma-radiation source nor SVG was a significant factor for the between-study variance (P value, 0.675 and 0.433, respectively); the adjusted between-study variance was 0.000. Intra-coronary brachytherapy is effective compared with placebo at mid-term follow up. Neither procedure in SVG (gamma radiation) nor difference in radiation source (beta or gamma) in native coronary arteries was a significant factor in brachytherapy effectiveness compared to placebo.